1. Field of the Invention
The present invention relates to a photosensitive material package inclusive of photographic film for example, and a packaging apparatus for the same. More particularly, the present invention relates to a photosensitive material package and a packaging apparatus in which a plurality of photosensitive materials can be collectively packaged.
2. Description Related to the Prior Art
Photographic film and photographic paper are photosensitive material, which is wound in a roll form and contained in a container called a cassette, cartridge or magazine (hereinafter referred to simply as a cassette) for the convenience in the handling. The cassette has a slit-like passage mouth for the purpose of unwinding and rewinding of the photosensitive material, and is not watertight. To protect the photosensitive material from moisture after the manufacture and before use, generally the cassette is contained in a single watertight case. The 135 type photo film is contained in a cassette of metal, which is contained in a plastic cylindrical "P case" as a watertight case, and further covered in a packaging box of paper in a form to be sold.
The photographic film of a 135 type sold commercially at the retail level. Sometimes packages having a plurality of photographic films are sold. JP-U (Japanese Utility Model Laid-open Publication No.) 52-148930 discloses a package in which a single packaging box covers plural P cases each of which contains a photo film cassette. Examples of packages with heat shrinkable film having perforations are disclosed in JP-U 58-113653, JP-A (Japanese Patent Laid-open Publication No.) 54-67421 and U.S. Pat. No. 5,020,669 (corresponding to JP-Y (Japanese Utility Model Publication No.) 6-17743), which are characterized by ease of packaging, and a structure with both "product virginity" (originality) and "openability", namely a structure openable easily prior to use after the purchase.
The conventional packaging apparatus wraps an object in shrinkable film loosely at first, and subjects a number of spots on the shrinkable film to heat sealing. The object covered in the shrinkable film is transported into a shrinking tunnel, through which the shrinkable film is heated so that the shrinkable film is tightly fitted around the object.
The package disclosed in JP-U 52-148930 has shortcomings of high cost of packaging material and producing operation utilizing adhesive agent, because a packaging box of paper is used for packaging plural P cases collectively. It is likely that the packaging box is torn during transportation or upon an accidental drop. It is difficult to keep virginity of products in consistency with openability. The package disclosed JP-U 58-113653 is a base sheet together with shrinkable film: the base sheet has perforations, and a plurality of dry batteries are tightly wrapped on the base sheet collectively block by block along trains of the perforations. There is little restriction in designing a process of packaging with the shrinkable film, because the packaged objects are the dry batteries. It is impossible to utilize the disclosure of this document for packaging of a plurality of photosensitive material.
JP-U 54-67421 discloses a package inclusive of perforated shrinkable film packaging a single P case which contains a cassette, in a fashion where a cap of the P case is prevented from being removed and the cassette has product virginity and openability. However this document does not disclose packaging of a plurality of P cases collectively in shrinkable film. It is impossible for the disclosure to solve problems in collective packaging, namely to achieve consistency of the product virginity and openability regarding each single cassette, and to avoid a visually unpleasant appearance with too many wrinkles. U.S. Pat. No. 5,020,669 discloses that each P case contains a cassette and is contained in a box, and that a plurality of boxes with such P cases are packaged in shrinkable film. There is a problem in high cost for the packaging, as the boxes as an intermediate packaging material for the respective cassettes are included.
The conventional packaging apparatuses have difficulties in packaging an object in shrinkable film. They have complex mechanisms, high cost, and are slow in operation. A number of spots on the shrinkable film are subjected to heat sealing. The packaging operation is slowed further when the number of spots for the heat sealing is increased.